Virtualized network function interworking

ABSTRACT

According to an example aspect of the present invention, there is provided a system comprising a memory configured to store a list of virtualized network functions, VNFs, active in a first Network ( 101 ), and at least one processing core configured to process a request, originating in a second network ( 102 ), requesting to run a first VNF in the first network on behalf of the second network, and based at least partly on the request, to cause instantiation of the first VNF in the first network.

FIELD

The present application relates to virtualized network functions incommunication networks.

BACKGROUND

Communication networks, such as for example cellular communicationnetworks, are comprised of network nodes. The network nodes of a networkmay be subdivided into different node types, for example, a cellularcommunication network may comprise base stations, base stationcontrollers, switches, gateways and application functions. An internetprotocol, IP, network may comprise routers and gateways.

When designing a network, planners may estimate loading situations in acoverage area of the network. For example, in busy sections of cities itmay be estimated that communication occurs more often, and at a higherintensity, than in outlying areas. Therefore, in the case of a cellularnetwork, cells in busier areas may be made smaller, and base stationsassigned to control these smaller cells may be furnished with sufficientdata processing capability to handle high peak loads. For example, thebase stations may be equipped with several data processing cards.Likewise, network nodes tasked with conveying data to and from basestations with high anticipated peak loads may be dimensioned to becapable of handling these high loads.

Virtualization of network functions may be employed to simplify networkmaintenance. In a network where functions have been, at least in part,virtualized, virtualized network functions may be run as softwareentities on server computers, which may be located in a datacentre, forexample. Depending on the type of network function being virtualized,for example depending on whether the function is simple or complex, avirtualized network function, VNF, may be split into multiple VNFcomponents, VNFCs. An example of a simple VNF is a firewall, while ahome location register is an example of a complex VNF.

Interworking of networks with each other may comprise, for example, thatgateway functions are arranged at edges of network domains, the gatewaysbeing arranged to convey information to and from the network domain inwhich they are comprised.

SUMMARY OF THE INVENTION

The invention is defined by the features of the independent claims. Somespecific embodiments are defined in the dependent claims.

According to a first aspect of the present invention, there is provideda system comprising a memory configured to store a list of virtualizednetwork functions, VNFs, active in a first network, and at least oneprocessing core configured to process a request, originating in a secondnetwork, requesting to run a first VNF in the first network on behalf ofthe second network, and based at least partly on the request, to causeinstantiation of the first VNF in the first network.

Certain embodiments of the first aspect may comprise at least onefeature from the following bullet ed list:

-   -   the at least one processing core is further configured to        allocate resources to the first VNF    -   the at least one processing core is further configured to        allocate resources to the first VNF dynamically    -   the system is configured to configure the first VNF with at        least one interface to the second network    -   the system is configured to compile first information,        describing an extent of resource usage of the first VNF in the        first network    -   the resources comprise at least one of electrical power,        increased radio interference, processing resources and memory        resources    -   the system is further configured to participate in resource        usage balancing with the second network based at least partly on        the first information    -   the system is further configured to participate in the resource        usage balancing at least partly based on second information,        describing an extent of resource usage of    -   second VNF in the second network, the second VNF being run on        behalf of the first network    -   the at least one processing core is further configured to        determine a need to increase resources allocated to the first        VNF, or detect spare capacity in the first network, and,        responsively, to obtain authorization from the second network to        increase the resources allocated to the first VNF in the first        network.

According to a second aspect of the present invention, there is provideda method comprising storing a list of virtualized network functions,VNFs, active in a first network, processing, in the first network, arequest originating in a second network, requesting to run a first VNFin the first network on behalf of the second network, and based at leastpartly on the request, causing instantiation of the first VNF in thefirst network.

Certain embodiments of the second aspect may comprise at least onefeature from the following bulleted list:

-   -   allocating resources to the first VNF    -   allocating resources to the first VNF dynamically    -   configuring the first VNF with at least one interface to the        second network    -   compiling first information, describing an extent of resource        usage of the first VNF in the first network    -   the resources comprise at least one of electrical power,        increased radio interference, processing resources and memory        resources    -   participating in resource usage balancing with the second        network based at least partly on the first information    -   participating in the resource usage balancing at least partly        based on second information, describing an extent of resource        usage of a second VNF in the second network, the second VNF        being run on behalf of the first network    -   determining a need to increase resources allocated to the first        VNF, and, responsively, obtaining authorization from the second        network to increase the resources allocated to the first VNF in        the first network.

According to a third aspect of the present invention, there is providedan system comprising means for storing a list of virtualized networkfunctions, VNFs, active in a first network, means for processing, in thefirst network, a request originating in a second network, requesting torun a first VNF in the first network on behalf of the second network,and means for causing instantiation of the first VNF in the firstnetwork based at least partly on the request.

According to a fourth aspect of the present invention, there is provideda non-transitory computer readable medium having stored thereon a set ofcomputer readable instructions that, when executed by at least oneprocessor, cause an apparatus to at least store a list of virtualizednetwork functions, VNFs, active in a first network, process, in thefirst network, a request originating in a second network, requesting torun a first VNF in the first network on behalf of the second network,and cause instantiation of the first VNF in the first network based atleast partly on the request.

According to a fifth aspect of the present invention, there is provideda computer program configured to cause a method in accordance with thesecond aspect to be performed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example system capable of supporting at least someembodiments of the present invention;

FIG. 2 illustrates an example network architecture in accordance with atleast some embodiments of the present invention;

FIG. 3 illustrates an example apparatus capable of supporting at leastsome embodiments of the present invention;

FIG. 4 illustrates signalling in accordance with at least someembodiments of the present invention;

FIG. 5 illustrates signalling in accordance with at least someembodiments of the present invention, and

FIG. 6 is a flow graph of a method in accordance with at least someembodiments of the present invention.

EMBODIMENTS

By running a virtualized network function, VNF, in a first network onbehalf of a second network, sharing of network resources can befacilitated. Such resources may include geographic reach and/orcomputational resources, for example. Scaling of resources allocated tothis virtualized network function may be made subject to authorizationfrom the second network, as usage of resources in the first network mayaffect a resource settlement between the first and second networks.

FIG. 1 illustrates an example system capable of supporting at least someembodiments of the present invention. In the system of FIG. 1, mobile110 has a wireless link 112 with radio node 122. Radio node 122 is areduced version of a base station, the radio node comprising radiohardware but less, or no, information processing functions. Radio nodes122 and 132 take the places of base station in the system of FIG. 1.Radio node 122 and radio node 132 are both separately connected withserver 1V1, which comprises a computer system configured with computingresources, such as processing cores and memory, arranged to be able torun the information processing capabilities of normal base stations thatare absent in the radio nodes of FIG. 1. In other words, at least partof information processing functions of normal base stations have beenplaced in server 1V1 in the system of FIG. 1.

The information processing functions relating to radio node 122 thattake place in server 1V1 are denoted as virtualized base station 120 v.The information processing functions relating to radio node 132 thattake place in server 1V1 are denoted as virtualized base station 130 v.

Server 1V2 is in the system of FIG. 1 configured to run virtualizedversions of core network nodes. In the system of FIG. 1, server 1V2 runsa virtualized core network node 140 v may comprise, for example, amobility management entity, MME, or a router. Core network node 140 v isfurther operably connected to further virtualized core network node 150v. Further core network node 150 v may comprise a gateway, for example,configured to provide access to further networks, such as the Internet,for example. In use, virtualized base station 120 v may receiveinformation from radio node 122 and perform processing operations on thereceived information. Virtualized base station 120 v may be configuredto forward information it has processed to virtualized core network node140 v in server 1V2, for example. A further server 1V3 may be comprisedin the system, being configured to run a virtualized subscriber register160 v, for example.

Servers 1V1, 1V2 and 1V3 may be based on generic computation technology,such as a set of x86-architecture multi-core processors or reducedinstruction set computing, RISC, processors, for example. Server 1V1need not be based on the same computation technology as server 1V2.

Mobile 110, radio nodes 122 and 132, as well as servers 1V1, 1V2 and 1V3are in the system of FIG. 1 comprised in network 101. A second network,102, is further illustrated in FIG. 1. For the sake of clarity, innetwork 102 is illustrated only one server, 1V4, although network 102may naturally comprise a plurality of further, non-illustrated, nodes.In FIG. 1, network 101 runs virtualized core network node 140 v onbehalf of network 102. Running a virtualized network function on behalfof another network comprises running this virtualized network functionin a server of the network, such that the virtualized network functionruns for the benefit of the another network. The virtualized networkfunction concerned may have an interface 1XX to the other network, forexample to a server comprised in the other network. Interface 1XX may beused to convey configuration information and/or network traffic. Theother network may be experiencing a shortage of capacity, or the othernetwork may lack coverage in a certain geographic area, for example.Alternatively or additionally to a virtualized core network node, avirtualized base station or indeed, in general another kind ofvirtualized network function may be run in a first network on behalf ofa second network. More than one virtualized network function may be sorun on behalf of the second network in the first network.

In general, a virtualized network function may comprise a softwareentity on generic computing hardware that is configured to perform, atleast in part, according to a same specification as a correspondingnetwork function that has not been virtualized, that is, one that runson dedicated hardware. By generic computing hardware it is meanthardware that is not designed to run a specific type of virtualizednetwork function. In other words, a virtualized network function maycomprise a software implementation of a logical network node of acommunication network. This has the effect that in terms of othernetwork elements, these other elements needn't know whether the networkelement has been virtualized or not. Therefore, a virtualized callsession control function, CSCF, for example, can be sent the same kindsof messages as a non-virtualized CSCF. A virtualized network function,VNF, may comprise of multiple virtualized network function components,VNFCs.

The system of FIG. 1 offers advantages over a system that lacksvirtualized network functions. In detail, virtualized base station 120 vmay be scaled according to need, whereas a non-virtualized base stationmust be dimensioned for the maximum expected load at all times. Forexample, when load is light, virtualized base station 120 v may be runwith a few, or only one, processing core in server 1V1, while otherprocessing cores of server 1V1 may be used for other processing tasks,such as grid computing, for example. As a response to increasing loadvia radio node 122, virtualized base station 120 v may be allocated moreprocessing cores in a dynamic network management action.

The system of FIG. 1 may perform network management actions, eachnetwork management action involving at least one virtualized networkfunction or virtualized network function component. virtualized networkfunctions may comprise, for example, virtualized base stations and/orvirtualized core network nodes. The network management action maycomprise at least one of the following: increasing resources allocatedto a virtualized network function or virtualized network functioncomponent, decreasing resources allocated to a virtualized networkfunction or virtualized network function component, starting avirtualized network function or virtualized network function componentinstance, and terminating a virtualized network function or virtualizednetwork function component instance.

Starting a virtualized network function or virtualized network functioncomponent instance may comprise initializing, for example based at leastin part on a template or image, a new virtualized network function orvirtualized network function component. In terms of FIG. 1, this mightcomprise, for example, initializing a further virtualized core networknode, “155 v” in server 1V2. The new virtualized network function, ornode, may be allocated resources in terms of at least one processor coreand memory. A new virtual network function may be considered onboardedonce associated software images/templates have been uploaded to thevirtual infrastructure and have been added to a list of virtualizednetwork functions, and instantiated once it has been assignedcomputational resources. Normally, virtualized network functions areboth onboarded and instantiated.

Terminating a virtualized network function may correspondingly compriseending processor tasks that run the virtualized network function.Terminating may be smooth in nature, wherein, for example, any usersserved by a virtualized network function that is to be terminated arehanded over to another virtualized network function, to avoid brokenconnections. Terminating may also be abrupt, for example where it isdetermined a virtualized network function is misbehaving, operators mayselect abrupt termination. Misbehaviour may be determined by comparing aVNF's behaviour to a behavioural pattern, for example.

The number of servers may be selected independently of the embodimentand network implementation. For example, one, three or seven servers maybe used. In general, a server is an example of a computation apparatusarranged to run virtualized network functions and/or virtualized networkfunction components. Such an apparatus may alternatively be referred toas a computational substrate.

In general, a node in a first network may process a request, originatingin a second network, requesting to run a first VNF on behalf of thesecond network. The request may comprise a description of the VNF thesecond network would like the first network to run, or a pointer to sucha description, for example. Accepting the request may be based ondetermining, whether the networks have an agreement in place thatenabled such actions. Where the request is accepted, the first networkmay begin to compile information concerning resources the VNF used inthe first network, while operating on the behalf of, and for the benefitof, the second network. A VNF running in the first network on behalf ofthe second network may be run on a computational substrate, such as aserver, comprised in the first network. Such resource use may bemonitored in terms of processing resources consumed, memory used, radiointerference caused and/or network interconnect capacity consumed. Wherean interface 1XX is enabled to the second network, the resources used bythis interface may be included in the monitoring.

In case the second network, in turn, runs one or more VNFs on behalf ofthe first network, the two networks may perform settlements concerningresources consumed by VNFs they run on behalf of each other. A goal ofsuch settlements may be to maintain at least a rough equivalence betweenresources the networks invest in running VNFs on behalf of each other,such that one of the networks does not become relatively more burdenedby hosting VNFs on behalf of another network. The settlements may beseen as a network management action, such that both networks maintainreasonable throughput in relation to their resource usage. In principle,a network may obtain a similar throughput with its resources if it runsVNFs on behalf of other networks, if it in turn has these other networksrun VNFs on its behalf, and benefits from throughput generated by theseVNFs.

In some embodiments, imbalances in resource use detected in settlementsmay be settled by monetary or other suitable transactions, such that thenetwork that uses less resources in running VNFs on behalf of the otherpays compensation to the other network.

FIG. 2 illustrates an example network architecture in accordance with atleast some embodiments of the present invention. FIG. 2 comprises, likeFIG. 1, networks 101 and 102. Each network may separately be consideredto be a system. The compound system o f network 101 and network 102 mayalso be considered to be a system. In FIG. 2, VNF 210 comprises avirtualized network function, such as for example a virtualized networkfunction as described above in connection with FIG. 1. VNF 210 has aninterface with VNF manager 230, wherein VNF manager 230 may beconfigured to initiate network management actions, for example,responsive to changes in a loading level of virtualized networkfunctions or responsive to a determined fault condition. VNF manager 230has an interface with virtualized infrastructure manager, VIM, 220. VIM220 may implement a monitoring function to detect virtualized networkfunctions that cross loading or other predefined thresholds, toresponsively trigger network management actions. For example, where aloading level exceeds a first threshold, more resources may be allocatedto the virtualized network function, and/or where the loading leveldecreases below a second threshold, resources may be allocated from thevirtualized network function to other uses. NFV orchestrator, NFVO, 270and/or another node may be configured to take a network managementaction with at least one operating condition of the network. Thearchitecture may comprise a plurality of VNFs 210, VIMs 220 and/or aplurality of VNF managers, VNFMs, 230.

Both VNF 210 and VIM 220 have interfaces to network functionsvirtualization infrastructure, NFVI, 240. NFVI 240 may provide a set ofhardware and software components that build up the environment in whichVNFs are deployed. VNF 210 further has an interface with elementmanager, EM, 250. EM 250 may provide end-user functions for managementof a set of related types of network elements which may include networkelements with virtualized network functions or non-virtualized networkfunctions, or both. These functions may be divided into two maincategories: Element Management Functions and Sub-Network ManagementFunctions. In some embodiments, EM 250 may be configured to takedecisions concerning network management actions, and to cause thedecisions to be implemented by signalling concerning them to VNF manager230, for example. EM 250 may take decisions concerning networkmanagement functions as a response to a determined fault condition, forexample. EM 250 has an interface with operational support systems and/orbusiness support systems, OSS/BSS 260. OSS/BSS 260 may be configured tosupport end-to-end telecommunication services. OSS/BSS 260 may implementload monitoring, for example. OSS/BSS 260 in turn has an interface withNFV Orchestrator, NFVO, 270. NFVO 270 may comprise a VNF catalogue, alist of known VNFs referred to above.

Network 102 comprises similar structure as network 101, in detail, VNF211, VIM 221, VNFM 231, NFVI 241, EM 251, OSS/BSS 261 and NFVO 271. Inthe compound system of FIG. 2, network 101 runs VNF 291 on behalf ofnetwork 102. Network 102, on the other hand, runs VNF 290 on behalf ofnetwork 101. VNF 291 is furnished with an interface to network 102, inthis example to VNF 211 of network 102. Likewise, in this example VNF290 is furnished with an interface to network 101, to VNF 210. Thus,network 102 may use VNF 291 as part of its processing chain of VNFs andnetwork 101 may use VNF 290 as part of its processing chain of VNFs.

VIMs of the respective networks, for example, may be configured tocompile the information concerning resources used by VNFs run on behalfof other networks. A VNFM, for example, may determine that a VNF run onbehalf of another network may need additional capacity. Responsively,such a VNFM may request scaling-up of capacity for this VNF, for examplefrom a NFVO. The NFVO may, before authorizing the scale-up, requestpermission from the network on behalf of which the VNF is being run, andonly once such permission is obtained, the NFVO will instruct the VNFMthat the scale-up may proceed.

While an EM may have an interface with a VNF or VNFC that is run onbehalf of another network, this is not necessarily the case. Forexample, where the VNF or VNFC is relatively simple, its configurationmay be part of an onboarding package, for example in a template or imageprovided. In these cases, it is assumed the configuration doesn't needfine tuning for the specific instance being requested to be run in ahosting network. An EM-VNF interface is illustrated in FIG. 2 as adotted line interface between EM 251 and VNF 291.

For example, a scale-up may be needed where subscribers of the othernetwork, who use the VNF run on behalf of the other network, usehigh-bandwidth services such as streaming high-definition media. Theother network may decide on allowing the scale-up, knowing that thescale-up will result in increased resources used on its behalf in thenetwork hosting the VNF, which will lead to demands, such as financialclaims, from the hosting network when resource usage is settled lateron. If the other network cannot afford the settlement with the scale-up,for example due to high load in its network, it may refuse the scale-up.In case the load is high, the other network may be unable to provide,via the settlement, corresponding resources to VNFs it hosts. Whenrefusing, the other network may configure bandwidth limits tosubscribers relying on the VNF run on behalf of the other network in thehost network, to thereby render the scale-up unnecessary. Generally, insome preferred embodiments of the present invention, the other networkis advantageously provided with an opportunity to enforce scaling orparticularly, dynamic scaling, of resources allocated to the VNF run inthe hosting network on behalf of the other network. Accordingly,situations wherein e.g. the hosting network autonomously up-scales (dueto e.g. extra capacity detected) or down-scales the resourcesdynamically to a level not tolerable by the other network, can becleverly omitted. The preferred procedure may involve proactivelynotifying or generally informing, by the hosting network or an elementfunctionally connected thereto, the other network about a future change(e.g. a suggested change, intended change, etc.) in the level ofresource usage in the hosting network for running the VNFs on behalf ofthe other network. The other network may then evaluate the effects ofthe change according to selected logic (e.g. in terms of cost or otherfactors) and allow or reject the change, and respond to the hostingnetwork accordingly. In some embodiments, the other network may e.g.initially agree on or inform the hosting network about the level ofresource usage (e.g. maximum, average, minimum) it tolerates or acceptsfrom the hosting network for duly executing the VNFs on its behalfwithout further negotiation. If the hosting network is about to gobeyond the agreed resource usage, it may notify the other network toobtain a permission as contemplated above. The information transferconcerned such as the aforementioned notifications may include e.g.transmission, conveying, and receipt of applicable signaling messagesbetween the relevant parties and potential intermediate entities asbeing easily understood by a person skilled in the art.

FIG. 3 illustrates an example apparatus capable of supporting at leastsome embodiments of the present invention. Illustrated is device 300,which may comprise, for example, a server of FIG. 1. Comprised in device300 is processor 310, which may comprise, for example, a single- ormulti-core processor wherein a single-core processor comprises oneprocessing core and a multi-core processor comprises more than oneprocessing core. Processor 310 may comprise more than one processor. Aprocessing core may comprise, for example, a Cortex-A8 processing coremanufactured by ARM

Holdings or a Steamroller processing core produced by Advanced MicroDevices Corporation. Processor 310 may comprise at least one AMD Opteronand/or Intel Core processor. Processor 310 may comprise at least oneapplication-specific integrated circuit, ASIC. Processor 310 maycomprise at least one field-programmable gate array, FPGA. Processor 310may be means for performing method steps in device 300. Processor 310may be configured, at least in part by computer instructions, to performactions.

Device 300 may comprise memory 320. Memory 320 may compriserandom-access memory and/or permanent memory. Memory 320 may comprise atleast one RAM chip. Memory 320 may comprise solid-state, magnetic,optical and/or holographic memory, for example. Memory 320 may be atleast in part accessible to processor 310. Memory 320 may be at least inpart comprised in processor 310. Memory 320 may be means for storinginformation. Memory 320 may comprise computer instructions thatprocessor 310 is configured to execute. When computer instructionsconfigured to cause processor 310 to perform certain actions are storedin memory 320, and device 300 overall is configured to run under thedirection of processor 310 using computer instructions from memory 320,processor 310 and/or its at least one processing core may be consideredto be configured to perform said certain actions. Memory 320 may be atleast in part comprised in processor 310. Memory 320 may be at least inpart external to device 300 but accessible to device 300.

Device 300 may comprise a transmitter 330. Device 300 may comprise areceiver 340. Transmitter 330 and receiver 340 may be configured totransmit and receive, respectively, information in accordance with atleast one cellular or non-cellular standard. Transmitter 330 maycomprise more than one transmitter. Receiver 340 may comprise more thanone receiver. Transmitter 330 and/or receiver 340 may be configured tooperate in accordance with Ethernet and/or worldwide interoperabilityfor microwave access, WiMAX, standards, for example.

Device 300 may comprise user interface, UI, 360. UI 360 may comprise atleast one of a display, a keyboard, a touchscreen, a vibrator arrangedto signal to a user by causing device 300 to vibrate, a speaker and amicrophone. A user may be able to operate device 300 via UI 360, forexample to manage actions regarding quarantined network nodes.

Processor 310 may be furnished with a transmitter arranged to outputinformation from processor 310, via electrical leads internal to device300, to other devices comprised in device 300. Such a transmitter maycomprise a serial bus transmitter arranged to, for example, outputinformation via at least one electrical lead to memory 320 for storagetherein. Alternatively to a serial bus, the transmitter may comprise aparallel bus transmitter. Likewise processor 310 may comprise a receiverarranged to receive information in processor 310, via electrical leadsinternal to device 300, from other devices comprised in device 300. Sucha receiver may comprise a serial bus receiver arranged to, for example,receive information via at least one electrical lead from receiver 340for processing in processor 310. Alternatively to a serial bus, thereceiver may comprise a parallel bus receiver.

Device 300 may comprise further devices not illustrated in FIG. 3. Insome embodiments, device 300 lacks at least one device described above.

Processor 310, memory 320, transmitter 330, receiver 340, NFCtransceiver 350, UI 360 and/or user identity module 370 may beinterconnected by electrical leads internal to device 300 in a multitudeof different ways. For example, each of the aforementioned devices maybe separately connected to a master bus internal to device 300, to allowfor the devices to exchange information. However, as the skilled personwill appreciate, this is only one example and depending on theembodiment various ways of interconnecting at least two of theaforementioned devices may be selected without departing from the scopeof the present invention.

FIG. 4 illustrates signalling in accordance with at least someembodiments of the present invention. On the vertical axes are disposed,from the left, network 102, EM 251, VNF 291, network 101, NFVO 270, VNFM230 and, finally, VIM 220. VNF 291 is run by network 101 on behalf ofnetwork 102. Time advances from the top toward the bottom. Network 101and network 102 may in this context refer to a management point of thesenetworks, respectively, for example.

An agreement between network 101 and network 102 on settling resourceusage may precede phase 410. In phase 410, network 102 providesinformation concerning a VNF it requests network 101 to run on itsbehalf. Such information may comprise a VNF template or image, or apointer to such a template or image, for example. Responsively, network101 may request 420 NFVO 270 to onboard and instantiate the new VNF.

NFVO 270 may validate the request, phase 430, and request VNFinstantiation from VNFM 230, phase 440, responsive to successfulvalidation in phase 430. VNFM 230 may process the request, and allocateinitial resources to the VNF in phase 450, by signalling to the NFVO270. In phase 460, NFVO 270 instructs VIM 220 to set-up the allocatedresources, and an interface from the new VNF to the requesting network,102. Responsively, in phase 470, VIM 220 allocates internal andinter-network connectivity. VIM 220 also allocates a virtual machine andattaches it to network 101, and then provides an acknowledgement back toNFVO 270, phase 480.

In phase 490, NFVO 270 acknowledges to VNFM 230 completion of resourceallocation. In phase 4100, VNFM 230 configured VNF 291, and in phase4110 VNFM 230 notifies EM 251 of successful VNF instantiation,concerning VNF 291. In phase 4120, EM 251 configured VNF 291.

In phase 4130, VNFM 230 acknowledged end of VNF instantiation to NFVO270, and NFVO acknowledges the same to network 101 in phase 4140.Finally, in phase 4150 network 101 informs network 102 of VNFinstantiation.

Overall via the process of FIG. 4, the VNF is instantiated in thehosting network, to run there on behalf of the requesting network. Beinginstantiated in the hosting network may comprise, for example, that theVNF runs on a computational substrate of the hosting network.

FIG. 5 illustrates signalling in accordance with at least someembodiments of the present invention. The vertical axes correspond tothose of FIG. 4. Overall the signalling sequence of FIG. 5 is anexample. In general, in various embodiments a trigger or request toscale may originate in nodes other than a VNFM. For example an NVFO

At the beginning of the process illustrated in FIG. 5, VNF 291 is run innetwork 101, on behalf of network 102. VNF 291 is provided with aninterface to network 102, to thereby communicatively couple it tonetwork 102.

In phase 510, VNFM 215 determines VNF 291 is in need of up-scalingresources, for example, that instead of a current two processor cores,VNF 291 would need ten cores. Responsively, VNFM 230 requests scalingfrom NFVO 270, phase 520.

NFVO 270 requests permission to scale-up the resources from network 101,which in turn requests permission, as described above, from network 102,phases 530 and 540, respectively. More generally, available extracapacity on the side of network 101 could be indicated towards network102 to enable network 102 to decide upon usage thereof. In theillustrated example, network 102 decides to allow the scaling-up, andindicates this back to network 101 in phase 550. Responsively, in phase560 network 101 instructs NFVO 270 to proceed with the scaling, and inphase 570 NFVO 270 instructs VNFM 230 to perform the scaling.

In phase 580, VNFM 230 performs the scaling. Finally, in phase 590 VNF291 informs network 101 of the change in resource usage, to therebyenable network 101 to participate in resource usage settlement withnetwork 102.

FIG. 6 is a flow graph of a method in accordance with at least someembodiments of the present invention. The phases of the illustratedmethod may be performed in a computational substrate of a network, suchas a server, for example, or in a control device configured to controlthe functioning thereof, when implanted therein.

Phase 610 comprises storing a list of virtualized network functions,VNFs, active in a first network. Phase 620 comprises processing, in thefirst network, a request originating in a second network, requesting torun a first VNF in the first network on behalf of the second network.Finally, phase 630 comprises, based at least partly on the request,causing instantiation of the first VNF in the first network.

It is to be understood that the embodiments of the invention disclosedare not limited to the particular structures, process steps, ormaterials disclosed herein, but are extended to equivalents thereof aswould be recognized by those ordinarily skilled in the relevant arts. Itshould also be understood that terminology employed herein is used forthe purpose of describing particular embodiments only and is notintended to be limiting.

Reference throughout this specification to one embodiment or anembodiment means that a particular feature, structure, or characteristicdescribed in connection with the embodiment is included in at least oneembodiment of the present invention. Thus, appearances of the phrases“in one embodiment” or “in an embodiment” in various places throughoutthis specification are not necessarily all referring to the sameembodiment. Where reference is made to a numerical value using a termsuch as, for example, about or substantially, the exact numerical valueis also disclosed.

As used herein, a plurality of items, structural elements, compositionalelements, and/or materials may be presented in a common list forconvenience. However, these lists should be construed as though eachmember of the list is individually identified as a separate and uniquemember. Thus, no individual member of such list should be construed as ade facto equivalent of any other member of the same list solely based ontheir presentation in a common group without indications to thecontrary. In addition, various embodiments and example of the presentinvention may be referred to herein along with alternatives for thevarious components thereof. It is understood that such embodiments,examples, and alternatives are not to be construed as de factoequivalents of one another, but are to be considered as separate andautonomous representations of the present invention.

Furthermore, the described features, structures, or characteristics maybe combined in any suitable manner in one or more embodiments. In thepreceding description, numerous specific details are provided, such asexamples of lengths, widths, shapes, etc., to provide a thoroughunderstanding of embodiments of the invention. One skilled in therelevant art will recognize, however, that the invention can bepracticed without one or more of the specific details, or with othermethods, components, materials, etc. In other instances, well-knownstructures, materials, or operations are not shown or described indetail to avoid obscuring aspects of the invention.

While the forgoing examples are illustrative of the principles of thepresent invention in one or more particular applications, it will beapparent to those of ordinary skill in the art that numerousmodifications in form, usage and details of implementation can be madewithout the exercise of inventive faculty, and without departing fromthe principles and concepts of the invention. Accordingly, it is notintended that the invention be limited, except as by the claims setforth below.

The verbs “to comprise” and “to include” are used in this document asopen limitations that neither exclude nor require the existence of alsoun-recited features. The features recited in depending claims aremutually freely combinable unless otherwise explicitly stated.Furthermore, it is to be understood that the use of “a” or “an”, thatis, a singular form, throughout this document does not exclude aplurality.

INDUSTRIAL APPLICABILITY

At least some embodiments of the present invention find industrialapplication in managing communication network interworking.

REFERENCE SIGNS LIST

101, 102 Networks 122, 132 Radio nodes 120v, 130v Virtualized basestations 140v, 150v Virtualized core network nodes 160v Virtualizedsubscriber register IV1, IV2, Servers IV3, IV4 110 Mobile 112 Wirelesslink 1XX Interface 210, 211 VNFs 220, 221 VIMs 230, 231 VNFMs 240, 241NFVIs 250, 251 Ems 260, 261 OSS/BSSs 270, 271 NFVOs 290, 291 VNFs run onbehalf of another network (hosted VNFs) 300-360 Structure of the deviceof FIG. 3 410-4150 Phases of signaling illustrated in FIG. 4 510-590Phases of signaling illustrated in FIG. 5 610-630 Phases of the methodof FIG. 6

1. A system comprising: means for storing a list of virtualized networkfunctions, VNFs, active in a first network; means for processing, in thefirst network, a request originating in a second network, requesting torun a first VNF in the first network on behalf of the second network;and means for causing instantiation of the first VNF in the firstnetwork based at least partly on the request.
 2. The system according toclaim 1, wherein the means for processing are further configured toallocate resources to the first VNF.
 3. The system according to claim 2,wherein the means for processing are further configured to allocateresources to the first VNF dynamically.
 4. The system according to claim1, wherein the system is configured to configure the first VNF with atleast one interface to the second network.
 5. The system according toclaim 1, wherein the system is configured to compile first information,describing an extent of resource usage of the first VNF in the firstnetwork.
 6. A method comprising: storing a list of virtualized networkfunctions, VNFs, active in a first network; processing, in the firstnetwork, a request originating in a second network, requesting to run afirst VNF in the first network on behalf of the second network; andbased at least partly on the request, causing instantiation of the firstVNF in the first network.
 7. The method according to claim 6, furthercomprising allocating resources to the first VNF.
 8. The methodaccording to claim 7, further comprising allocating resources to thefirst VNF dynamically.
 9. The method according to claim 6, furthercomprising configuring the first VNF with at least one interface to thesecond network.
 10. The method according to claim 6, further comprisingcompiling first information, describing an extent of resource usage ofthe first VNF in the first network.
 11. The method according to claim10, wherein the resources comprise at least one of electrical power,increased radio interference, processing resources and memory resources.12. The method according to claim 10, further comprising participatingin resource usage balancing with the second network based at leastpartly on the first information.
 13. The method according to claim 12,further comprising participating in the resource usage balancing atleast partly based on second information, describing an extent ofresource usage of a second VNF in the second network, the second VNFbeing run on behalf of the first network.
 14. The method according toclaim 6, further comprising determining a need to increase resourcesallocated to the first VNF, and, responsively, obtaining authorizationfrom the second network to increase the resources allocated to the firstVNF in the first network.
 15. The method according to claim 6, furthercomprising detecting available capacity in the first network andobtaining authorization from the second network to increase theresources allocated to the first VNF based thereon.
 16. A computerprogram configured to cause a method according to claim 6 to beperformed, when run.